Another Dunalastair model.

Any aspect related to the prototype stock.
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dunalastairv
Posts: 209
Joined: Wed Dec 12, 2012 7:01 am

Another Dunalastair model.

Post by dunalastairv »

With regard to Caledonian locomotive models found in unusual places, there is on 'You Tube' a 19min. 22 sec. video entitled "Portrait of an Engineer", made by Merton Park Studios, and mainly following the work of an Engineer at the Vulcan Foundry at Newton-le-Willows, Lancashire, in the early-1950s. Towards the end of this film there is a class room scene which features a superb model of a Dunalastair, probably in 5" or even 7" gauge - it's difficult to be sure as the sequences are short. Does anyone know the history of this model, if it still exists, and where it is now?

Thanks in advance, Michael.
jim mac
Posts: 636
Joined: Mon Aug 13, 2012 7:20 pm

Re: Another Dunalastair model.

Post by jim mac »

Michael
A fascinating piece of film.
The Dunalastair appears to be unpainted, judging by the shine. Why it is in a college in NW England is a mystery.

The following screenshots may be of interest in allowing further study.
You tube Dunalastair 1 (reduced).jpg
You tube Dunalastair 1 (reduced).jpg (65.28 KiB) Viewed 8630 times
You tube Dunalastair 2 (reduced).jpg
You tube Dunalastair 2 (reduced).jpg (59.12 KiB) Viewed 8630 times
dunalastairv
Posts: 209
Joined: Wed Dec 12, 2012 7:01 am

Re: Another Dunalastair model.

Post by dunalastairv »

Thank you Jim for your expertise in finding these screen shots, they're really helpful and enable a far more detailed view than the fleeting glimpse in the film itself. It looks a fine piece of work...
Graham R
Posts: 73
Joined: Sat Sep 14, 2013 8:44 am

Re: Another Dunalastair model.

Post by Graham R »

Here is yet another Dunalastair model, this time in 3½” gauge. It seems it may date from the 1920s: I wonder if the paintwork is the original?

Regards
Graham
dunalastairv
Posts: 209
Joined: Wed Dec 12, 2012 7:01 am

Re: Another Dunalastair model.

Post by dunalastairv »

Just to let people know, I purchased this 'Dunalastair' model at the Stoneleigh Auction on Saturday and it's now safely here. It is in rather a state though and certainly couldn't be steamed without major work. It was apparently made about 1904 - 6 by a Taff Vale fitter at Treherbert shed in South Wales, and retains its original paint, which is now very degraded. Further research is taking place and I hope to write an article about it for TTL in due course.

Michael.
Mike 1
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Joined: Tue Feb 12, 2019 8:46 pm

Re: Another Dunalastair model.

Post by Mike 1 »

Michael, can you please explain the "oil fired" mentioned in the catalogue? Do they mean spirit fired - i.e. meths?

Also, that seems to me (though I am no expert!) to be very early for 3 1/2in gauge as many models were 3 1/4in at that period.

A lovely period model which still looks good 100 years after it was built. Superb.

Mike
dunalastairv
Posts: 209
Joined: Wed Dec 12, 2012 7:01 am

Re: Another Dunalastair model.

Post by dunalastairv »

Good morning, Mike,

Thanks for your message: first of all, let me say the model is definitely 3 1/2" gauge - that's the distance between the flanges and I need to source some good quality track for it to sit on.

The fuel arrangements are definitely odd, and of course, rather home made, as this engine was entirely scratch-built, using any materials that could be found on scrap piles in South Wales. My guess is that it was powered by meths, but the actual burner in the firebox is missing completely. The fuel supply consists of a cylinder, 3 1/2" in diameter and 3" deep, which sits at the back of the tender tank, and which has what looks like a bicycle tyre valve on top. It's substantial and obviously intended to be pressurised. From it leads a brass tube to a tap which must then have been connected to the burner itself. Does this provide any clues?

The model arrived with the smokebox door handle and wheel missing. Can anyone direct me towards supplies of these components in 1:16 gauge?

Many thanks, Michael.
Mike 1
Posts: 49
Joined: Tue Feb 12, 2019 8:46 pm

Re: Another Dunalastair model.

Post by Mike 1 »

Thank you Michael.

The chances of finding a CR wheel and dart in 3 1/2in are remote, but what does that make the diameter of the model wheel? Since the wheel is quite small, I just might have something in 2 1/2in.

Pressurised sounds more like paraffin than meths to me, about which I now nothing!

Paul Norman Plastics make track that is inexpensive. I suspect this will be a centrepiece for your model railway room? About 20 years ago I did the same, buying a 2 1/2in Gauge LNWR 4-6-0 Experiment model from about 1908. It looked nice and I thought about building maybe just one wagon to go with it, and maybe another ... and I've not built any 7mm since, but have several dozens of 2 1/2in wagons. So beware, the bug can bite!

Mike
dumb buffer
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Joined: Tue Aug 14, 2012 10:13 pm

Re: Another Dunalastair model.

Post by dumb buffer »

Off the cuff, there are various suppliers in the model engineering field of parts and castings for "Rob Roy", which is a 3 1/2" guage live steam Beetlecrusher.
Might there be something suitable there?

Allan F
DonaldPeddie
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Joined: Sat Sep 22, 2012 2:40 pm

Re: Another Dunalastair model.

Post by DonaldPeddie »

Most interesting to read of the Dunalastair IV model. Just over 12 months ago I acquired a 2.5" gauge Dunalastair IV Superheater Model, No 139, complete with bogie tender. The loco was built around 50/60 years ago, has a superheated boiler (2 flues with single return loops) and an operational steam brake. Cylinder lubrication is by pressurising mechanical lubricator. The motion is Joy valve gear as it is impossible to find enough room at 2.5" gauge to fit valve gear eccentrics and rocking levers. Valve chests are on top of the cylinders.

When I acquired the model, it had lain untouched for 25/30 years and was seized. Much time and patience was expended on getting it to its present state, where the motion now works properly and the steam brake is operational (on compressed air). Getting a boiler certificate for a boiler of this vintage, recognising the current Pressure Vessel Regulations is a complex matter and, without drawings, usually needs independent stress analysis of the boiler shell together with hydraulic testing.

I have set out some of the problems involved in restoration of older live steam models in a forthcoming TTL article, the experience being focused on a Pickersgill 191 Class 4-6-0 which I acquired at the same time.

For those in the restoration game and who wish to fit accurate model parts to replace missing components, i.e. door wheel and dart, etc, you have to make the parts yourself.

A picture of the Dunalastair IV model is attached.

Donald
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Mike 1
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Re: Another Dunalastair model.

Post by Mike 1 »

Donald, as a 2 1/2in gauge modeller myself with a leaning to CR and LNWR, this is right up my street. I wonder if any commercial parts were used in your model. For instance does it have full Joy vavegear or the Greenly modified (gravedigger) type? If the wieghshaft is cast bronze that would be a clue. Carson was the major manufacturer of the day, often bringing out new models within months of the real engine appearing.

Mike
DonaldPeddie
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Joined: Sat Sep 22, 2012 2:40 pm

Re: Another Dunalastair model.

Post by DonaldPeddie »

Hello Mike,

I've no experience of making Joy or any radial valve gears, my building being focused at scales where there is always lots of room for Stephenson's or Walschaerts' motion - usually at 7.25" gauge.

I've attached an image of the loco when the boiler was removed so that I could free the seized motion. The image shows the re-assembled components. As you will see the expansion link/weighshaft is a fairly substantial bronze casting. Unfortunately there are no drawings for any part of the loco, though I suspect in outline it would have been built from a works general arrangement drawing. The valve gear may have come from a Model Engineer series of articles. My reason for assuming that a works GA was used arises since I have a partially completed CR Class 55 4-6-0 in 3.5" gauge, by the same builder. For the 55 Class, which is also driven by Joy motion, I have a set of drawings in some detail for the loco, which were prepared by the builder around the early 1960s and are based on a works GA for the 55 Class, which I also have. There are detailed drawings for the Joy valve gear, which I suspect were to the builders own design, or modified from an existing proprietory design. I am presently completing a new boiler for the 55 Class, and sorting out the Joy gear, so one day it may return to steam.

At present I have no plans to steam the Dunalastair, as I'm convinced the boiler would not pass the current pressure vessel statutory requirements (I am the boiler examiner for our local MES). Whilst the boiler appears to be all copper, flanged and silver soldered, the foundation ring appears to be brazed and there are a number of areas where soft solder (Comsol or otherwise) has been used, possibly for caulking, which of course precludes the further use of silver solder.

The paint is original, hand brushed, and I would not want to further damage it. Any information you can supply on the Joy valve gear would be much appreciated.

Donald
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Mike 1
Posts: 49
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Re: Another Dunalastair model.

Post by Mike 1 »

Beautiful Donald. Would look good at the head of my 2pm corridor set.

Anyway, Joy valvegear. It is not all commercial parts because some bits are not the same shape as commercial bits, though I suspect hat weighshaft casting may be by Lowke? Greenly tried to simplify the design, do doing away with the anchor link which goes forward beneath the axleboxes and is usually, on models, secured to the front horns or even the rear of the cylinders. One problem with Joy gear in model form is the width, with two pairs of links beside the con rods and if you beef up the rods and links for better wear, it all gets a bit tight under there! So, one of his ideas changed the connecting rod to be T shaped with a downward extension near the centre, with just one pair of links from there to the slippers in the weighshaft.

Here is the underside of my Carson LNWR Experiment fro about 1910.

Mike
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Experiment valvegear.JPG
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Mike 1
Posts: 49
Joined: Tue Feb 12, 2019 8:46 pm

Re: Another Dunalastair model.

Post by Mike 1 »

And here is a drawing of Carson's version of Joy valvegear for 2.5in gauge, from Model Engineer of (I think) 1906. Carson and Geenly/Lowke had running battles in the press at that time, so there is no way Carson would use Greenly's altered valvegear, though he did claim to have used something similar previously and concluded that the full version was much better. But then he would wouldn't he!

Carson was the bigger firm and when they overstretched themselves and called in the received, the story goes that Lowke was waiting on the factory steps to buy up all the designs and tooling which they then re-introduced under their own name. Must have been hard marketing designs which you had recently rubbished in the press!

Mike
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Carson valvegear.jpg
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Mike 1
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Re: Another Dunalastair model.

Post by Mike 1 »

Sorry to dominate this thread but one thought Donald - I assume your boiler is under 3bar litre, so subject to different testing rules? I assume you are under Northern Federation testing rules whereas I use Southern Fed, but I am sure they must be similar.

Mike
Angus McIntosh
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Re: Another Dunalastair model.

Post by Angus McIntosh »

Michael,

The 'Model Engineer and Amateur Electrician' in 1901 ran a constructional series by E.L.Pearce on building a Dunalastair III .
The series ran in issues 42,44,46,48 & 50 from Vol 4, and 54,56 & 58 from Vol 5.
It was designed with a prototypical fire tube boiler suitable for spirit, paraffin (Primus) and 'charcoal' firing, with details for the burners and grate included.
From these the details you require might be obtained, and the current Model Engineer magazine includes advertisements from sub-contract machinist who might be able to manufacture the required parts.

Regards

Angus
dunalastairv
Posts: 209
Joined: Wed Dec 12, 2012 7:01 am

Re: Another Dunalastair model.

Post by dunalastairv »

Dear Angus,

I'm grateful for your advice. Over the last week or so I've looked at the possibilities of obtaining parts for my model and the general conclusion has always been that I need to have them made. I will get a copy of the Model Engineer and see if that's a way forward.

Many thanks, Michael.
CR906
Posts: 11
Joined: Mon Apr 22, 2013 8:09 pm

Re: Another Dunalastair model.

Post by CR906 »

With regards to the Dunalistair IV in the Vulcan Foundry film. I dont know if it is the same model, but the Institute of Mechanical Engineers (IMechE) have on display an unpainted model of a Dunalastair IV numbered 140 at their offices at Birdcage Walk, London and details can be found on their website in their archive section (no photo). Note their spelling of Dunalastair in case you use the search facility on their archive web pages which you dont need to be a member to use. Extract from the webpage shown below.

Ref No ; IME/13/7/14
Alt Ref No ; MUS/17
Title ; Model Caledonian Railway locomotive
Date ; 1904
Description ;
4-4-0 locomotive of the final Dunalister Class, No.140, with double-bogie tender, designed for the Caledonian Railway by J F McIntosh. The model was originally designed to use oil fuel, but was altered in 1924 to burn coal, the working pressure being 90lb per sq. inch. W H Dearden was the first gold medalist of the Society of Model & Experimental Engineers and received numerous other awards. Scale: 3/4 inch to 1 foot.

Physical Description ; Steel and brass, contained in a glazed oak case with a mirrored base
Dimensions ; 1160x240x145mm

i haven't been to a meeting there in the last couple of years, but if i can i will see if i can obtain a photo or two.
George Davidson
CR906
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Re: Another Dunalastair model.

Post by CR906 »

Find 3 photos of the Dunalastair model at the IMechE. it is tucked away in a corner so not too easy to photograph.
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Dunalastair at IMechE
Dunalastair at IMechE
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Dunalastair at IMechE
Dunalastair at IMechE
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Dunalastair at IMechE
Dunalastair at IMechE
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George Davidson
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